Unprecedented α-cyclodextrin metal-organic frameworks with chirality: Structure and drug adsorptions

An assembly of cyclodextrin metal-organic frameworks (CD-MOFs) has aroused extensive research interests due to their excellent encapsulation capacity and biocompatibility. In this work, starting from the chiral building block α-cyclodextrin (α-CD), a novel α-CD-MOF compound with left-handed chiral helices, [Na(H 2 O)(C 36 H 60 O 30 )]·H 2 O (Na-α-CD-MOF), was synthesized through changing the diffusion solvent, and then structurally characterized. Single crystal X-ray diffraction analysis reveals that Na-α-CD-MOF exhibits a 3D left-handed helical chiral framework with large cavities (740   Å 3 ). The result of a drug adsorption assay shows Na-α-CD-MOF possesses a more efficient drug adsorption capacity than α-CD matrix, and the solubility of the drug adsorbed in Na-α-CD-MOF can be greatly enhanced. All the results, including the lower cytotoxicity, indicate that Na-α-CD-MOF is an excellent kind of renewable, environmental friendly and biocompatibility drug carrier material.